Hi, I'm John! I will help you with this.
You can change the default app for PDF files in Windows 11 by doing this:
- Click Start. > Open Settings. > Go to Apps. > Select Default apps.
- In the search box, type .pdf. > Click the current default app beside .pdf.
- Choose your PDF reader, such as Adobe Acrobat Reader. > Click Set default or confirm the change.
You can also do it this way:
- Right-click any PDF file > select Open with > Choose another app > select your PDF reader > check Always use this app to open .pdf files > click OK.
May I ask which PDF reader you want to use? Also, does that PDF reader already appear in the list of default apps?